全文获取类型
收费全文 | 528篇 |
免费 | 30篇 |
国内免费 | 1篇 |
专业分类
林业 | 131篇 |
农学 | 3篇 |
66篇 | |
综合类 | 59篇 |
农作物 | 8篇 |
水产渔业 | 23篇 |
畜牧兽医 | 242篇 |
园艺 | 4篇 |
植物保护 | 23篇 |
出版年
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 9篇 |
2014年 | 16篇 |
2013年 | 30篇 |
2012年 | 15篇 |
2011年 | 23篇 |
2010年 | 18篇 |
2009年 | 24篇 |
2008年 | 19篇 |
2007年 | 13篇 |
2006年 | 11篇 |
2005年 | 16篇 |
2004年 | 16篇 |
2003年 | 15篇 |
2002年 | 16篇 |
2001年 | 12篇 |
2000年 | 8篇 |
1999年 | 6篇 |
1998年 | 15篇 |
1997年 | 13篇 |
1996年 | 12篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1979年 | 4篇 |
1973年 | 4篇 |
1971年 | 4篇 |
1967年 | 5篇 |
1959年 | 9篇 |
1953年 | 6篇 |
1937年 | 11篇 |
1936年 | 9篇 |
1934年 | 4篇 |
1933年 | 4篇 |
1932年 | 3篇 |
1931年 | 16篇 |
1930年 | 4篇 |
1929年 | 10篇 |
1928年 | 6篇 |
排序方式: 共有559条查询结果,搜索用时 15 毫秒
1.
The technique of liver puncture as described by Holtenius (1961) was assessed with regard to its practicability and safety in a preliminary study of 26 cattle and a follow-up study of 108 German black pied cattle. The sample material was smeared, stained and examined by light microscope. All animals with changes of grade 5 had to be slaughtered. Liver puncture is a simple, quick and safe technique which supplies useful information about the various stages of hepatic fatty degeneration in individual cattle. 相似文献
2.
Current German law on animal rights requires protection and appropriate treatment of animals. However, information on breeding and raising swine is incomplete, and comparison studies of alternative housing systems are needed. Therefore, the effects of single and group housing of pregnant sows on piglet production was investigated in the 120-sow herd of the Institute for Animal Breeding and Husbandry of the University of Kiel. Reproductive traits, general health and behaviour studies were evaluated over one year. Type of housing system was found to have no effect on number of piglets born alive or dead or on days open. Daily gain was influenced. Daily gain of single-housed sows increased but without any difference in feed intake. General health was measured by nutritional condition, soiling, callosity, and injuries at time of evaluation. Single-housed sows had more calluses and were more soiled compared with group-housed sows. Injuries occurred more often in group housing, especially when new animals were integrated into the group. However, injuries were not serious. Animal behaviour was recorded on video during one pregnancy period of 60 sows. The housing system effected "sitting" and "lying" behaviour. Behaviour also is influenced by pregnancy in both housing systems. Equal incidences of abnormal behaviour, considered as sham-chewing, were found in both housing systems. 相似文献
3.
4.
5.
Fabricius Fritz Ernst Reinhold Haenel und Bogtherr 《Forstwissenschaftliches Centralblatt》1933,55(21):758-770
Ohne Zusammenfassung 相似文献
6.
7.
8.
9.
10.
Ernst Knippel Röhrl Schüpster Schaile und Fabricius 《Forstwissenschaftliches Centralblatt》1927,49(19):687-703
Ohne Zusammenfassung 相似文献